Water-soluble esters of pregnanolones



"a JV" WATER-SOLUBLE ESTERS 0F PREGNANOLONES Gerald D. Laubach, JacksonHeights, N. Y., assignor to Chas. Pfizer & Co., 1110., New York, N. Y.,a corporation of Delaware No Drawing. Application January 7, 1955,Serial:N0. 480,614

14 Claims. (Cl. 167-52) This invention is concerned with certain novelsteroid compounds. In particular it is concerned with certain novelsteroid compounds which are hormonally inactive and useful as centralnervous system depressants, especially as anesthetic agents.

This application is a continuation-in-part of application Serial No.463,805, filed on October 21, 1954, by Gerald D. Laubach, and nowabandoned.

The compounds of this invention are the first steroids of practicalutility as central nervous system depressants, and they are particularlyuseful as anesthetic agents, since they have advantages over anypreviously known anesthetic. This invention comprises the unexpecteddiscovery that central nervous system depressants maybe prepared bymaking certain hormonally inactive steroids water-soluble through theaddition of an ionic group of a particular kind. While there are somevariations in the effects of these compounds depending upon theindividual in which D and B have meanings to be defined below. Thisgeneric formula includes both compounds of the pregnane series and alsocompounds of the allopregnane series, i. e. compounds of the formula andalso compounds of the formula D may be a monovalent group, and it may bea divalent group. When D is monovalent, of course there is also ahydrogen atom at the 3 position, but when D is a divalent group, thereis no hydrogen.

D and/ or E is a polar group which is a salt of an acid ester of apolycarboxylic acid, or a salt of an amino acid ester. In thisapplication the term ionic ester is used to describe this type of group.There are two kinds of ionic esters, each of which is defined below.

The first kind of ionic ester has the formula o-oLooM+ I! H o in which Lis chosen from the group consisting of (CH2)n-, O-(CH2)nand -NH(CH2)n-,n being a number from 1 to 6, and M+ is a cation selected from the classconsisting of Na+, K NH4+ and derivatives of the ammonium ion in whichthe substituents are chosen from alkyl, hydroxy-. alkyl,- acylo'xyalkyl,arninoalkyl, aryl and aralkyl groups containing up to 10 carbon atoms ineach group. The following formulas will illustrate some of the variousderivatives of the ammonium ion.

The second kind of ionic ester has the formula in which L is chosen fromthe group consisting of i (CH2)n-, -O-(CH2)n-- and --NH-(CH2)n-, n beinga number from 1 to 6, Y+ is an ammonium function substituted with groupsChosen from hydrogen, alkyl, hydroxyalkyl, aminoalkyl, aryl and aralkylgroups containing up to 10 carbon atoms in each group, and Z- is apharmacologically acceptable anion. The following illustrate some of thevarious formulas for Y+.

The term pharmacologically acceptable anion has a definite meaning toone skilled in the art. It is defined as a non-toxic anion of any of thesimple acids commonly used in pharmacology to neutralize basic medicinalagents when the salt thereof is to be used therapeutically. These acidsinclude, for example, hydrochloric, hydrobromic, hydroiodic, sulfuric,succinic and maleic. The pharmacological activity of the molecule isprimarily a function of the cation, the anion serving chiefly to supplyelectrical neutrality.

As mentioned above, at least one ionic ester group is always in themolecule. Either D or B may be another group. E may be hydroxyl orhydrogen. D may be a keto group, a hydroxyl group or an oxime. Thehydroxyl group at D or E may be esterifiecl with non-ionic ester groups(i. e. ordinary ester groups, such as acetate or propionate, other thanionic ester groups) containing from 1 to 8 carbon atoms in the addedmoiety. The oxime group at D may also be esterfied with ordinary (i. e.non-ionic) ester groups, or it may be esteriiied with an ionic estergroup. This is summarized by saying that D is selected from the groupconsisting of:

n. Ionic ester groups,

b. Hydroxyl and non-ionic esters thereof containing from 1 to 8 carbonatoms in the added moiety,

' i c. Oxime, non-ionic esters thereof containing from 1 to 8 carbonatoms in the added moiety, and ionic esters thereof, and

d. Keto and E is selected from the group consisting of:

a. Ionic ester groups,

b. Hydroxyl and non-ionic esters thereof containing from 1 to 8 carbonatoms in the added moiety, and

0. Hydrogen with at least one ionic ester group always being present inthe molecule.

The ionic ester group, at least one of which is always present in eachcompound, renders the compounds watersoluble because of its ionicnature. As is seen from the foregoing,'this group is present in any ofthree ways:

1. It is on the 21 position carbon;

2. It is on the 3 position carbon;

3. It is on an oxime group which is on the 3 position carbon. Sometimestwo ionic ester groups, which may be the same or different, are present,the possible combinations here being (1) and (2), and (1) and (3) above.

It has now unexpectedly been discovered that these novel compounds have.properties which make them very valuable. They are central nervoussystem depressants, and they are hormonally inactive. They are useful asanesthetic, anti-convulsant, sedative, analgesic andhypnotic agent's.Their water solubility is such that they may be administeredintravenously insterile aqueous solution. They are also suitable foradministration by other routes such as orally, subcutaneously andintramuscularly.

selected from the class consisting of 3 and 21 in a SterQid having thenucleus.

C=O CH:

Filtration through a Seitz filter is a convenient method of sterilizinga solution of a compound of this invention. The compounds may also beemployed in aqueous solutions containing other solutes, for example,enough saline or glucose to make them isotonic. The compounds may becombined with a variety of pharmaceutically acceptable carriers, thechoice of which will depend upon the desired method of administration.For example, the compounds may be administered orally in the form oftablets containing tablet forming material such as starch, or as anelixir or suspension in a carrier.

The methods for preparing these compounds are illustrated in theexamples given below. It is to be understood that most of these examplesdemonstrate a general method of preparation applicable to not only theparticular cornpound being discussed in that example but also tocompounds of a similar chemical nature, for instance compounds differingin only the value of n in the formulas given above for the ionic esters,or in only the configuration at the 5 position.

There are, of course, variations in the effects of the compounds of thisinvention depending upon the particular substituents. Each, however, hasthe three common characteristics of being hormonally inactive, active asa central nervous system depressant, and water-soluble.

The following examples are given solely for the purpose ofillustration,'and are not to be regarded as limitations of thisinvention, many variations of which are possible without departing fromits spirit or scope.

EXAMPLE I ZI-hydroxypregna'ne-S, ZO-dione hemisuccinate salts A solutionof g. of desoxycorticosterone in 190 ml. of absolute ethanol was stirredin an atmosphere of hydrogen in the presence of 1.68 g. of palladium oncalcium carbonate catalyst. After 20 hours, approximately 1 molarequivalent of hydrogen had been absorbed and hydrogen uptake had ceased.The catalyst was removed by filtration and the filtrate evaporated invacuo to yield 20 g. of nearly pure product, M. P. 40 C. The crudeproduct was demonstrated to be free of starting material by paperchromatography. A highly purified product was obtained byrecrystallization from acetone-water with cooling in an ice bath, yield14.5 g., M. P. l52154 C. The product was characterized by analysis andby absence of ultraviolet absorption.

A solution of 14 g. of 21-hydroxypregnane-3, 20-dione and of 14 g. ofrecrystallized succinic anhydride in ml. of dry pyridinewas allowed tostand at room temperature for 18 hours, then cooled in an ice bath andpoured in a fine stream into 1.5 l. of ice water. Excess pyridine wasneutralized with 3N hydrochloric acid and the solution further dilutedwith 2 l. of ice water. The precipitated product was filtered, washedwith water and dried in vacuo at 50 C. affording 18 g. of solid M. P.192-195 C. Recrystallization of a small sample afforded analyticallypure material, M. P. 200 C.

The N,N tetramethyl hexamethylenediamine salt of the hemisuccinate wasprepared as a clear solution by adding 200 mg. of the hemisuccinate to188 mg. of the diamine and adding the mixture to 10 ml. of water. Thesalt as a white solid was obtained by lyophilization.

The dimethylamino ethanol, diethylamino ethanol, di-

EXAMPLE II 21-hydr0xypregnane 3,Z0-dione sodium hemisuccinate To a drymixture or" g. of the hemisuccinate of Example I and 1.867 g. of sodiumbicarbonate was added, in small portions, 200 ml. of water with slightheating and evacuation. A clear, essentially colorless solution of thesodium salt resulted. The solution was sterilized by filtration througha Seitz filter after addition of Super-cel and the filtrate was thenlyophilized at high vacuum. The

fiulfy white sodium salt, 9.65 g., was characterized by analysis and byultraviolet spectrum, Gmax 280=93.2.

EXAMPLE IlI 21-hydroxypi'egnane-3,20-a'i0ne dimethylamino acetatemethochloride To a solution of 21-hydroxypregnane-3,20-dione in pyridinewas added 2 molar equivalents of chloroacetyl chloride. After 12 hoursthe chloroacetate was isolated by precipitation with a large volume ofdilute, acidified ice water. The filtered and dried chloroacetate wasreacted in dimethylformamide solution with slightly more than 1 mole oftrimethylamine. Careful dilution of the reaction medium resulted in theprecipitation of the desired methochloride, characterized by analysisand its ready solubility in water.

EXAMPLE IV 30,21dihydr0xypregnane-ZO-one-Z1-hemisuccinatc salt One gramof 3a,21-dihydroxypregnane-ZO-one in 10 ml. of pyridine was allowed toreact for 4 hours with 1.2 molar equivalents of succinic anhydride. Theproduct, isolated by dilution and acidification of the reaction mixtnre,was characterized as the 21-mono-hemisuccinate by its ready solubilityin dilute sodium bicarbonate solution and by oxidation to theIll-hemisuccinate of 21-hydroxypregnane-3,20-dione.

The disuccinate was obtained by reaction of the 3,21-dihydroxypregnane--one with 5 molecular equivalents of succinicanhydride at 80 C. overnight.

EXAMPLE V 3a,21-zlihydroxypregnane-ZO-one-Zl-acetate salts A solution of4.4 g. of the pregnanedione 2l-acetate and 300 m1. of absolute ethanolwashydrogenated over 5.24 gof W-2 Raney nickel catalyst. After 20 hours1 molar equivalent of hydrogen had been absorbed. The product wasisolated by' removal of the catalyst by filtration and evaporation ofthe filtrate to yield'4.6 g., M. P. 169-175" C. Recrystallization of thecrude product from methanol yielded an analytical sample of the hydroxyacetate, M. P. 190.2-1945" C., characterized by analysis and byidentification of acetate and 1 carbonyl band in the infrared spectrum.

The 3-hemisuccinate was prepared from the above hydroxy acetate inexcess succinic anhydride by warming in pyridine solution to 80 C. for12 hours. The product, isolated by dilution and acidification, wascollected by extraction into ether and evaporation to dryness. The crudehemisuccinate was triturated with ether to afford a crystalline product,M. P. 179-181 C., characterized by its solubility in dilute sodiumbicarbonate solution.

The B-diethylamino acetate ethochloride was prepared from the3ot-hydroxy-2l-acetate by formation of the chloro acetate withchloroacetyl chloride in pyridine foluseful.

lowed by alkylation of the crystalline chloro acetate withtriethylaminel- The product 'was characterized by analysis and by itssolubility in water.

EXAMPLE VI Pregnane-3a-o[-20-one-3-hemisuccinate salt A solution of 500mg. of pregnanolone and 500 mg. of recrystallized succinic anhydride in5 ml. of dry pyridine was refluxed under nitrogen for 4 hours. Thereddish solution was poured into ice water and neutralized with 3Nhydrochloric acid. The precipitated product was separated by filtrationas a white solid, weight 571 mg., M. P. 203.4-208 C. The product wascharacterized by ready solubility in dilute sodium bicarbonate solution.

EXAMPLE VII 21 -hydr0xypregnane-3, 20-dione-[3-dimethyl-aminoethylcarbonate salts A solution of 1.00 gram of 21-hydroxypregnane-3, 20-dione in 5 ml. of benzene was added dropwise to a cooled, stirredsolution of 0.5 grams of phosgene in 5 ml. of benzene containing 1 ml.of pyridine. The solution was 7 stirred 2 hours at 25 C. and evaporatedto dryness in vacuo. The residue was 2l-hydroxypregnane-3, 20-dionechloroformate. It was treated with 2 ml. of fl-dimethylaminoethanol andallowed to stand 18 hours. Dilution with aqueous potassium carbonateprecipitated the fl-dimethylaminoethyl carbonate, which was extractedwith chloroform, and, after evaporation of the chloroform,recrystallized from methanol. The compound readily formed salts andquaternary ammonium compounds. For example, it was converted to thehydrobromide with ethereal hydrogen bromide and to the methiodide withmethyl iodide.

Alternate preparation of 21 -hydroxypregnane-3, 20-di0ne-[i-dimethylaminoethyl carbonate Although the preferred method 'of makingthis compound is that given above, the following method is also One halfgram. of fl-chloroethyl chloroformate was added to a stirred, cooledsolution of one gram of 21- hydroxypregnane- 3,20-dione in 5 ml. ofpyridine and the solution allowed to stand 24 hours. It was then stirredinto 20 ml. of ice cold 3N sulfuric acid, and extracted three times with15 ml. of chloroform. After washing with 1N sulfuric acid, water, andsodium bicarbonate solution, the chloroform extract was dried overanhydrous sodium sulfate and evaporated to dryness in vacuo. Triturationof the residue with ether yielded the crystalline 2l-hydroxypregnane-3,20 -dione B-chloroethyl carbonate which was converted to thediethylaminoethyl carbonate by refluxing it with an alcoholic solutionof diethylamine for 2 hours. The mixture was cooled, treated withsaturated aqueous potassium carbonate and extracted with chloroform,which was then evaporated to give the product.

EXAMPLE VIII 1 IydrOxyPregJzane-i ZO-dione ,B-diethylaminoethylcarbamate salts One gram of 2l-hydroxypregnane-3, ZO-dione chloro}formate, the preparation of which is shown in the first half of ExampleVII, was treated with 2 ml. of B-diethylaminoethylamine and allowed tostand for 18 hours. Dilution with aqueous potassium carbonateprecipitated the fl-diethylaminoethyl carbamate, which was extractedwith chloroform, and, after evaporation of the chloroform,recrystallized from methanol. The compound readily formed salts andquaternary ammonium compounds. For example, it was converted to thehydrobromide with ethereal hydrogen bromide and to the methiodide withmethyl iodide.

7 Alternate preparation of 21 -hydroxypregnane-3, 20-dionep-diethylaminoethyl carbamate Although the method above is preferred,another method of making this compound is as follows. One gram of2l-hydroxypregnane-3, 20-dione was dissolved in ml. of dimethylformamideand treated with 0.6 gram of f3- ehloroethylisocyanate. After standing18 hours, the mixture was poured into water, and the precipitatedproduct filtered off and washed with water. The product was 21-hydroxypregnane-B, 20-dione fi-chloroethyl carbamate, which wasconverted to the diethylaminoethyl carbamate by refluxing it with analcoholic solution of diethylamine for 2 hours. The mixture was cooled,treated with saturated aqueous potassium carbonate and extracted withchloroform, which was evaporated to give the product.

EXAMPLE IX Reaction of chloroforntate with hydroxy acids One gram of21-hydroxypregnane-3, 20-dione chloroformate, prepared as shown in thefirst half of Example Vll, was added to 5 ml. of pyridine containing 0.5gram of glycollic acid, and the mixture was allowed to stand for 18hours. It was then stirred into 20 ml. of ice cold 3N sulfuric acid, andextracted three times with ml. chloroform. After washing with 1Nsulfuric acid and with water, the chloroform extract was dried overanhydrous sodium sulfate and evaporated to dryness in vacuo. Theresulting compound had the formula where R stands for2l-hydroxypregnane-3, ZO-dione, minus its ZI-OI-l group. Treatment ofthis compound with dilute sodium bicarbonate produced the correspondingsodium salt.

These reactions were also carried out in an analogous fashion, withsimilar results, using other hydroxy acids.

EXAMPLE X Reaction of chloroformate with amino acids Example IX wasrepeated, except glycine was used in place of glycollic acid. Theresulting compound had the formula R0C-NCH2COOH where R stands for21hydroxyprcgnane-3, ZO-dione, minus its 21-OH group. Treatment of thiscompound with dilute sodium bicarbonate produced the correspondingsodium salt.

These reactions were also carried out in an analogous fashion. withsimilar results, using other amino acids.

EXAMPLE XI 2I-hydr0xypregnane-3, ZO-dione diethylamino acetatehydrochloride To a solution of 2 g. of the dried chloro acetate of 21-hydroxypregnanedione (Example III) in ml. of dry pyridine was added 1m1. of diethylamine. After standing overnight at 60 C., the solution waspoured into water, neutralized with sodium bicarbonate, and extractedwith methylene chloride; Evaporation of the extract afforded21-hydroxypregnanedione diethylamino acetate as the non-crystalline freebase. When the base was dissolved in ether-petroleum ether and treatedwith gaseous hydrochloric acid, the crystalline hydrochlorideprecipitilted as a White solid. The assigned structure was demonstratedby the ready solubility of the product in water.

, EXAMPLE XII 21 '-hydroxypregnane-3, 20 -dione piperadinoacetate hydro-I chloride procedure-ofExampleXI was repeated except that piperidine wassubstituted for the'diethylamine.

8 EXAMPLE x111 21-hydr0xypregnane-3, ZO-dione diethylaminoacetatemethobromide The free base (Example XE), ZI-hydroxypregnanc-3, ZO-dionediethylaminoacetate was treated with excess methyl bromide at roomtemperature in diemethylformamide solution. Dilution of the reactionmixture resulted in the precipitation of the methobromide.

EXAMPLE XIV 21-lzyaroxyallopregnane-3, 20-di0ne sodium hemisuccinate 10grams of 21-acetoxy A -pregnen-3B-ol-20-one was dissolved in 50 ml. ofredistilled dioxane and hydrogenated at 10 pounds per square inchpressure in the presence of 1 g. of 5% palladium-on-charcoal catalyst.The rate of uptake of hydrogen sharply decreased after the adsorbtion ofone mole of hydrogen, and the hydrogenation was stopped. The catalystwas removed by filtration. Evaporation of the filtered solution todryness afforded a white crystalline residue of21-acetoxyallopregnan-3pol-20-one, which was dissolved in 40 ml. ofacetic acidbenzene (1:1) and oxidized directly by slow addition at 5 C.of 1.5 molar equivalents of chromic anhydride in 25 ml. of glacialacetic acid. Evaporation of the benzene-acetic acid in vacuo to lowvolume and dilution with 100 m1. of water yielded crude product as awhite precipitate which was recovered by filtration. Tworecrystallizations from methanol afforded essentially pure21-acetoxyal1opregnanedione, M. P. 181-186 C.

The same product was obtained by an alternate procedure as follows:catalytic hydrogenation of desoxycortiosterone acetate (2 g.) overPd(CaCos) catalyst in ml. of ethanol at atmospheric pressure affordedafter removal of catalyst and solvent a crude product, M. P. 131-142 C.,which was directly chromatographed over 120 g. of Florisil. From thebenzene and 1:10 etherbenzene eluates was isolated21-acetoxypregnanedione, M. P. l48151 C. From the later benzene-etherand ether fractions was isolated by evaporation and recrystallization,21-acetoxyallopregnanedione, M. P. l84l89 C., identical to the materialprepared from 21-acetoxy A pregnen-SB-ol-ZO-one.

The purified 2l-acetoxyallopregnane-Ii, 20-dione was hydrolyzed byrefluxing 1 g. of it dissolved in ml. of aqueous methanol containingsodium carbonate. The 21-hydroxyallopregnanedione was isolated afteracidification, dilution with water, and partial evaporation. It was thendried in vacuo, dissolved in 10 ml. of dry pyridine, and reactedovernight with 1.0 g. of succinic anhydride. Dilution of the reactionmixture with dilutc acid and ice, and filtration of the precipitatedsolid afforded 21-hydroxyallopregnanedione succinate as a mass of tinyneedles.

The sodium salt was prepared by reacting 500 mg. of the crystallinesuccinate with one equivalent of sodium bicarbonate in 3 ml. of water.The diluted solution (20 ml.) was frozen and lyophilized at high vacuumto afford 2l-hydroxyallopregnanedione sodium succinate as a white solid,which was found to be an active anesthetic on intravenous injection inexperimental animals.

Similarly, other ionic esters of 21-hydroxyallopregnanedione wereprepared using conditions identical to preparation of the pregnaneisomers. Once the steroid nucleus had been prepared, the preparation ofionic esters, at the 21 and also at the 3 position, was the same in theallopregnane series as in the pregnane series, since the isomerism atthe 5 position had no effect on these reactions.

EXAMPLE XV 3 3-hydroxyallopregnane-ZO-one sodium succinate A solution ofone gram of A -pregnadien-3/8-ol-2O- one in 50 ml. of acetic acid washydrogenated at atmospheric pressure over one gram of an active 5%palladium-on-charcoal catalyst. After adsorbt ion of .2 moles ofhydrogen, the reaction was interrupted and the product3fi-hydroxyallopregnane-20=onerecovered by filtration of catalyst andevaporation of the filtrate to dryness. The recrystallized product wasdissolved in ml. of pyridine and treated overnight with l g. of succinicanhydride. Dilution with 3N hydrochloric acid yielded a whiteprecipitate of BB-hydroxyallopregnane-ZO- one succinate, which wasrecovered by filtration.

The sodium salt was prepared by reacting the dried acid with one molarequivalent of sodium hydroxide in 10 ml. of water and lyophilization toa white solid.

EXAMPLE XVl Pharmacological testing of typical compounds with mice21-hydr0xypregnane-3, ZO-dione sodium hemisuccinate.When this compound,in sterile aqueous solution was injected intravenously intomice, adosage of 21.7 mg./kilogram body weight was sufficient to producehypnosis in 50%. HD50=21.7 mg./kg. The lethal dosage required to kill.50% (LDso) was 250 mg./kg. This means that the therapeutic ratio (TR),which is the ratio of LDsn to HDso, was 11.5. (The therapeutic ratio ofthe well known hypnotic agent sodium pentothal is approximately Whenadministered subcutaneously, the HDso of this novel compound wasapproximately 35 mg/kg. By the oral route, the HDso was 100 mg./kg.

A further advantage of this compound lies in the fact i that animalsanesthetized with it recover with a minimum of post-anestheticdepression.

3a-lzydroxypregnane-ZO-one-sodium hemisuccinate.- Wheninjected'intravenously in a sterile aqueous solu tion, the HDso of thisnovel compound was 29 mgkg. The LD50 was approximately 115 trig/kg, andthe therapeutic ratio was therefore approximately 4.

By the oral route, the HDso was approximately 100 mg'jkg. 1

21-hydr0xypregnane-3, ZO-dionaprocaine hemisnccz mate-When injectedintravenously in a sterile aqueous solution the HDso of this novelcompound was approximately 37 mg./kg. By the oral route, the i-lDso wasapproximately 100 mg./ kg.

'21- hydrate-3, -di0ne-diethy!aminoethanol hemisuccinate.This compound,intravenously, produced 'anes thetic effect in dosages as low as mg/kg.Orally, anesthetic effect was produced by dosages as low as 125 rug/kg;I 1

21-hydr0xypregnane-3, ZO-dione dimethyibenzylaminehemisuccinate.1ntravenously, the HDsa of this compound was 19 mg./kg.Orally, it produced anesthetic elfect in dosages as low as 125 mg./kg.

Z1 -lzydr0xypregnane-3, ZO-dione triethylaminehemisuccinate.lntravenously, the HDso of this compound was 20 EXAMPLEXVII Pharmacological testing with dogs Dogs given intravenous injectionof to mg. of 2l-hydroxypre'gnane-3, ZO-dione sodium hemisuccinate perkg. lost consciousness in an average of three to five minutes andremained in this state for 50 to minutes. A total of six dogs receivedintravenously 50 mg. of this compound per kg. body weight. Theygenerally remainedin a state of light anesthesia and responded to painstimulation. Two of four dogs which received 100 mg. of the compound perkg. body weight remained in a state of surgical anesthesia forapproximately two hours.

A surgical operation (removal of a tumor from the chin) was performed onone dog after intravenous injection of 200 mg. of 21-hydroxypregnane-3,20-dione sodium hemisuccinate per kg. body weight. The operation lastedabout 40 minutes. The animal stood the operation well without anystruggle. The dogimade an uneventful recovery after the operation.

This is summarized by saying that A dog which was given intravenousinjection of 250 mg. of 2l-hydroxypregnane-3, 20-dione sodiumhemisuccinate per kg. body weight remained in a state of surgicalanesthesia for approximately three hours. The animal also recovered fromanesthesia.

Toxicity was also studied. One dog received daily 50 mg. per kg. andanother 100 mg. per kg. of 2l-hydroxypregnane-3, 20-dione sodiumhemisuccinate for a period of ten days. Hypnosis or light anesthesia wasobserved persistently during the ten day period with the dog receiving50 mg. of the compound per kg. The dog which received 100 mg. per kg.also went into a state of anesthesia following each daily injection; Onestriking phenomenon observed in these animals was that the duration ofsleep remained constant during the ten day period. In other words, notolerance to the compound was observed in these animals. At the end often days both dogs were sacrificed and tissues and organs were examinedgrossly and specimens taken for histopathological examination. Routinehematological examination including hemoglobin determination, white andred blood cell counts, liver function tests and blood chemistry of bothdogs were determined both at the beginning and end of the test period.All of these findings were within normal limits of variation.

EXAMPLE XVIII Pharmacological teszlng with monkeys 2l-hydroxypregnane-3,ZO-dione sodium hemisuccinate, was administered to two monkeys.

One monkey was given a dose of 50 trig/kilogram intravenously. Hereyelids drooped almost immediately and within seven minutes she wasasleep. The monkey did not respond to pinching; corneal reflexes wereabsent. One hour following the administration of the anesthetic, sheawoke and sat up; however, she was slightly ataxic. Within eightminutes, she was able to pick up a piece of apple and transport itdirectly to her month without any ataxic movements. The animal atenormally. Within seventeenminutes of awakening, the animal wascompletely normal. The animals respiration and heart rate did not changefrom control levels during the period of anesthesia.

The second monkey received a dose of 100 mg. per kilogram. I-ler eyelidsdrooped and her muscles relaxed almost immediately followingadministration of the compound. Within three minutes, the animal laystill and did not respond to ear or skin pinching. The corneal reflexwas absent and the eyes were fixed; After one hour and thirty-twominutes, the animal shook her head and lifted it after having herearpinched. She was definitely drowsy and ignored food. Within fourminutes, she showed a slight tremor of the facial muscles. This wasaccentuated when the animal tried to get up. Eight minutes afterawakening, the animal was more observant, but still lay quietly. Threeminutes later, she changed her position, sitting on her haunches, andshe was more alert. There was no significant change in heart rate orrespiratory rate and character throughout the period of the experiment.

Although the foregoing illustrative examples have been concerned withdata on mice, dogs and monkeys, this is not to be construed as alimitation of this invention, the novel compounds of which are usefulfor administration to other animals, including human beings, and areparticularly useful and valuable for use in veterinary and humansurgery.

The following demonstrate preparation of some of the new intermediatesfor the novel end products of this invention:

ZI-hydmxypregnane-S, ZO-dione hemisuccinvited-grime To a solution of 860mg. of 2Lhydroxypfegnarte-3,19- dione hemisuccinate in 10 ml.'of 200proof alcohol cortaining 2 ml. of pyridine was added mg. of hydroxyiamine hydrochloride. The clear yellow reaction mixture was refluxedunder nitrogen for 2 hours, then evaporated in vacuo to a white glasswhich crystallized spontaneously on trituration with 100 ml. of icewater and 40 ml. of methanol. The essentially pure oXime was obtained byfiltration, weight 828 mg., M. P. l05-ll0 C. with decomposition.Recrystallization from isopropanol yielded an analytically pure sample,M. P. 105l09 C. with decomposition. Anal.Calcd. for: N, 3.13. Found: N,3.71.

30:,21-dihydr0xypregnane-20-0ne A solution of 2 g. of2l-hydroxypregnane-3, 20-dione in .85 ml. of absolute ethanol wasstirred in the presence of 3 g. of W-2 Raney nickel catalyst in anatmosphere of hydrogen. After 20 hours, slightly more than 1 molarequivalent of hydrogen had been absorbed and hydrogen uptake had ceased.The catalyst was removed by filtration on super-eel and the productobtain by evaporation of the filtrate in vacuo. The product wascharacterized by the appearance of intense hydroxyl absorption andcarbonyl absorption equivalent to only 1 ketone function in theinfrared.

21-hydroxypregnnne-3,20-di0ne acetate A solution of 5 g. ofdesoxycorticosterone acetate in 155 ml. of absolute ethanol washydrogenated in the presence of 1.25 g. of 25% palladium on calciumcarbonate catalyst. After 22 hours, 1 molar equivalent of hydrogen hadbeen absorbed and hydrogen uptake ceased. The product was obtained byremoval of the catalyst by filtration and evaporation of the filtrate todryness in vacuo, yield 4.4 g., M. P. 15015l C The product wascharacterized by absence of ultraviolet absorption at 240 m and byabsence of starting material by paper chromatography.

3.20-pregnanedine A solution of 50 g. of progesterone in 950 ml. ofethanol was shaken vigorously under an atmosphere of hydrogen in thepresence of g. of 5% palladium on carbon catalyst, adding in a slurryconsisting of 4 g. of potassium hydroxide in 80 ml. of water. In lessthan 2 hours, approximately 1 molar equivalent of hydrogen had beenabsorbed and hydrogen uptake ceased. The catalyst was removed byfiltration on a filter-aid, and the filtrate acidified with acetic acidand evaporated in vacuo to a small volume. Dilution of the precipitatewith one liter of water and filtration afforded 53 g. of nearly pureproduct, M. P. ll2ll6 C. The crude precipitate was dissolved in 250 ml.of acetone and crystallization induced r by careful addition of warmwater. The pure product obtained as three crops consisted of 34 g., M.P. ll9-l20 C., with no ultraviolet absorption at 240 m3u-hydr0xypregnane-ZO-one Ten grams of pregnanedione was dissolved in 50ml. of ethanol and hydrogenated over 5 g. of W-2 Raney nickel catalyst.The product, obtained after filtration and evaporation of the filtrateto dryness, amounted to 8.3 g., M. P. ll9-l26 C. Seven and two-tenthsgrams of the crude product was recrystallized from acetone-water andmethanol to afford an analytically pure sample, M. P. l40.8l42.0 C., [a]D+98.3. Only 1 carbonyl band was observable in the infrared spectrum.

Preg'nanedione 3-0xime A solution of 2.56 g. of pregnanedione in 40 ml.of absolute ethanol containing 4 ml. of pyridine and 56] mg. ofhydroxylamine hydrochloride was refluxed under nitrogen for 2 hours.Evaporation in vacuo afforded a white solid which was triturated withwater and dried to yield 2.667 g. of the monoxime, M. P. l60.4162.8 C.Anal.Calcd. for CmHssOr. N: N, 4.22; Found: N, 4.48.

The 3-hemisuccinate was prepared by warming 1 g. of the oxime and l g.of succinic anhydride in l0 ml. of

pyridine to C. for 12 hours. The product was isolated by dilution withwater and acidification.

What is claimed is: l. A compound having the formula in which D isselected from the group consisting of:

(a) Ionic ester groups having the formula --oo-LO-oM+ ll I and ionicester groups having the formula O-(HJLNRQ+Z- wherein L is chosen fromthe group consisting of -(cH2)n, -O--(CH2)n and -NH(CH2)n-, n being anumber from 1 to 6, M+ is a cation selected from the class consisting ofNa+, K and NR4+, each R represents a member of the group consisting ofhydrogen and alkyl, hydroxyalkyl, hydrocarbon carboxyalkyl, aminoalkyl,aryl and aralkyl groups, each containing up to ten carbon atoms, and Z-is a pharmacologically acceptable anion,

(b) Hydroxyl and hydrocarbon carboxylic acid esters thereof containingfrom 1 to 8 carbon atoms in the added moiety,

(c) Oxime, hydrocarbon carboxylic acid esters thereof containing from 1to 8 carbon atoms in the added moiety, and ionic esters thereof asdefined above, and

(d) Keto, and in which E is selected from the group consisting of:

(a) Ionic ester groups as defined above,

([1) Hydroxyl and hydrocarbon carboxylic acid esters thereof containingfrom 1 to 8 carbon atoms in the added moiety, and

(c) Hydrogen, with at least one of D and E being an ionic ester group asdefined above.

2. A pharmaceutical composition which comprises a compound as claimed inclaim 1 together with a pharmaceutically acceptable carrier.

3. An anesthetic agent comprising a sterile aqueous solution of acompound as claimed in claim 1.

4. 21-hydroxypregnone-3, ZO-dione diethylaminoacetate hydrochloride.

5. 2l-hydroxypregnane-3, 20-dione sodium hemisuccinate.

6. An anesthetic agent comprising a sterile aqueous solution of thecompound claimed in claim 5.

7. The triethylamine salt of 2l-hydroxypregnane-3, 20-dionehemisuccinate.

8. 21-hydroxyallopregnane-3, 20-dione sodium hemisuccinate.

9. Pregnane-3a-ol-20-one-3-sodium hemisuccinate.

10. A salt of a lower hydrocarbon aliphatic aminoacid ester of2l-hydroxypregnane-3, 20-dione and a pharmacologically acceptable anion.

11. A sodium salt of an acid ester of 2l-hydroxypregmane-3, 20-dionewith a lower hydrocarbon aliphatic di carboxylic acid.

12. A lower hydrocarbon substituted amine salt of an acid ester of2l-hydroxypregnane-3, 20-dione with a lower hydrocarbon aliphaticdicarboxylic acid.

13 13. A sodium salt of an acid ester of 21-hydroxyallopregnane-3,20-dione with a lower hydrocarbon aliphatic dicarboxylic acid.

14. A sodium salt of an acid ester of 3-hydroxypregmane-ZO-one with alower hydrocarbon aliphatic dicar- 5 boxylic acid.

References Cited in the file of this patent UNITED STATES PATENTS2,156,275 Butenandt May 2, 1939 10 2,173,423 Miescher Sept. 19, 19392,182,920 Hartmann 2- Dec. 12, 1939 2,183,589 Reichstein Dec. 19, 193914 Schwenk Dec. 24, 1940 Marker Feb. 11, 1941 Marker Feb. 11', 1941Reichstein Mar. 2, 1943 Linch Oct. 10, 1944 Ruzicka Oct. 14, 1947 SalkinApr. 21, 1953 Murray Nov. 24, 1953 FOREIGN PATENTS Switzerland May 16,1938 Switzerland Nov. 16, 1939

1. A COMPOUND HAVING THE FORMULA